Polycrystalline Patterns in Far-From-Equilibrium Freezing: A Phase Field Study

Published

August 1, 2006

Author(s)

L Granasy, T Pusztai, T Borzsonyi, G Toth, G -. Tegze, James A. Warren, Jack F. Douglas

Abstract

We discuss the formation of polycrystalline microstructures with the framework of phase field theory. First, the model is tested for crystal nucleation in a hard sphere system. It is shown that, when evaluating the model parameters from molecular dynamics simulations, the phase field theory predicts the nucleation barrier for hard spheres accurately. The formation of spherulites is described by an extension of the model that incorporates branching with a definite orientational mismatch. This effect is induced by a metastable minimum in the orientational free energy. Spherulities are an extreme example of polycrystalline growth, a phenomenon that results from the quenching of orientational defects (grain boundaries) into the solid as the ratio of the rotational to the translational diffusion coefficient is reduced, as is found at high undercoolings. It is demonstrated that a broad variety of spherulitic patterns can be recovered by changing only a few model parameters.

Citation

Polycrystalline Patterns in Far-From-Equilibrium Freezing: A Phase Field Study

Volume

86 No 24

Pub Type

Others

Keywords

grain boundaries, phase filed study, polycrystalline patterns

Citation

Granasy, L. , Pusztai, T. , Borzsonyi, T. , Toth, G. , Tegze, G. , Warren, J. and Douglas, J. (2006), Polycrystalline Patterns in Far-From-Equilibrium Freezing: A Phase Field Study, Polycrystalline Patterns in Far-From-Equilibrium Freezing: A Phase Field Study (Accessed April 25, 2024)